I have a Merry Mac 4.5" PTO
chipper. It's a different name plate on the MacKissick, sold by Northern. It's a decent quality machine but has a few drawbacks. Most notably the chips and shreddings just fall out of thebottom. Do much in one place and the pile reaches the bottom of the shredder and starts to plug up the outlet. So you have to move the
chipper about every 20-30 minutes. Kind of a pain if you have a big pile. And the pile ends up where you parked the tractor, so if it's on a road you have to shovel it out of the way. With a discharge chute you can spray the chippings out in to the woods.
The shredder is nice for small stuff and for green material that will pass through a
chipper without much change. It makes nice compost. The model you're looking at had half the shredding hammers mine has. It'll still work but you'll have to feed small branches and twigs a few at a time. The 3.5"
chipper on that model sounds pretty small. Mine (4.5") works for small stuff but I have to cut it up so there's no side branches. The brush I have grows crooked and these chippers work best on straight limbs. Being a self-feed
chipper blade sharpness affects feed speed. When the blades are sharp it'll pull branches out of your hands. I was running mine on a Kubota
B7100HST with 13 pto hp. It was a little underpowered but did ok. I have a
Woodmaxx WM-8H on a 32 pto HP Branson now. It's far more effective than the MacKissick. Witrh the hydraulic feed there's less reaching into the chute (carefully) to get a chunk to feed. So it's safer.
If you're mostly chipping branches and not shredding for compost you could go with the 6" hydraulic feed chippers from
Woodmaxx or Woodland Mills. A bit over your budget but much more capable. Of course if you buy the MacKissick and it's not enough you can sell it for about what you paid for it.